Ward C B, Glaser D A
Proc Natl Acad Sci U S A. 1970 Sep;67(1):255-62. doi: 10.1073/pnas.67.1.255.
The pattern of new growing forks in the Escherichia coli genome after a period of inhibition of DNA synthesis has been examined. Synchronous cultures of E. coli B/r were treated with nalidixic acid to stop DNA synthesis for various lengths of time. After removal of the nalidixic acid the location of active growing forks was determined by measuring the reversion rate of a histidine requirement induced by the "growing-point mutagen," nitrosoguanidine. It was found that the ability to initiate a new round of DNA synthesis upon release from the nalidixic acid block was attained at the cell age at which a new round of replication would have been initiated had DNA synthesis not been blocked. However, if the nalidixic acid was removed before the normal initiation age, the initiation of the next round of synthesis was delayed past the normal time, which indicates that initiation of new rounds is not completely independent of DNA synthesis.
研究了在一段DNA合成受抑制时间后，大肠杆菌基因组中新生长叉的模式。用萘啶酸处理大肠杆菌B/r的同步培养物，以在不同时长内停止DNA合成。去除萘啶酸后，通过测量由“生长点诱变剂”亚硝基胍诱导的组氨酸需求回复率，确定活跃生长叉的位置。结果发现，从萘啶酸阻断中释放后启动新一轮DNA合成的能力，在细胞达到正常情况下如果DNA合成未受阻本应启动新一轮复制的年龄时获得。然而，如果在正常起始年龄之前去除萘啶酸，下一轮合成的起始会延迟到正常时间之后，这表明新一轮的起始并非完全独立于DNA合成。
